disable self connections by default

now that the event manager can create files, self connections may create
even more issues than before

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/dataprovider/dataprovider.go

@@ -195,6 +195,7 @@ var (
 	lastLoginMinDelay            = 10 * time.Minute
 	usernameRegex                = regexp.MustCompile("^[a-zA-Z0-9-_.~]+$")
 	tempPath                     string
+	allowSelfConnections         int
 	fnReloadRules                FnReloadRules
 	fnRemoveRule                 FnRemoveRule
 	fnHandleRuleForProviderEvent FnHandleRuleForProviderEvent
@@ -804,6 +805,11 @@ type Provider interface {
 	resetDatabase() error
 }
 
+// SetAllowSelfConnections sets the desired behaviour for self connections
+func SetAllowSelfConnections(value int) {
+	allowSelfConnections = value
+}
+
 // SetTempPath sets the path for temporary files
 func SetTempPath(fsPath string) {
 	tempPath = fsPath

internal/dataprovider/user.go

@@ -497,6 +497,9 @@ func (u *User) GetPermissionsForPath(p string) []string {
 }
 
 func (u *User) getForbiddenSFTPSelfUsers(username string) ([]string, error) {
+	if allowSelfConnections == 0 {
+		return nil, nil
+	}
 	sftpUser, err := UserExists(username)
 	if err == nil {
 		err = sftpUser.LoadAndApplyGroupSettings()